[WIP] Two fixes related to making PHPCR-ODM work

- Changed requirements on routes to use .* to allow full paths
- Use ->find($id) instead of ->findBy(array('id' => $id)) which would
  never work with PHPCR-ODM

Relates to PR on core bundle: https://github.com/sonata-project/SonataCoreBundle/pull/82
retrieving the parent on creating would be a good thing, as it would reveal mistakes with a missing parent more clearly, rather than some confusing exception on save. but maybe we can't retreive the parent at the place we handle creation.